Understanding Availability Factor
How we calculate. AF % = hours available ÷ hours in period × 100. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.
Real-world scenario: A typical Availability Factor case uses available hours 680 and period hours 720. Enter the same figures below to reproduce the worked path.
What is Availability Factor?
A reliability KPI for generating units. Distinct from manufacturing OEE availability (run÷planned production time).
- Available = able to run per GADS/policy
- Same period hours
- Pairs with forced outage rate
The Formula
Worked Example
Common Use Cases
- Plant KPIs: unit availability
- Outage planning: available vs period
- PPA reviews: availability commitments
Pro Tips
- Align with GADS definitions
- Separate planned vs forced
- Don’t confuse with capacity factor
Limitations: Availability Factor results are educational energy and utilities planning aids—not engineering, grid-operations, or investment advice. Confirm definitions with your ISO/RTO, plant, and regulatory reporting standards.
FAQ
Same as OEE availability?
No. OEE availability is manufacturing run time vs planned production time. This page is generating-unit available hours vs period hours.
What if period hours is 0?
Availability factor is undefined—enter positive period hours.
Authoritative References
For power system and plant performance concepts, consult: